Can't bind to 'ngModel' since it isn't a known property of 'input'

Hey Guys ,

Today let's look at the following error :

'Can't bind to 'ngModel' since it isn't a known property of 'input"

This will come in case of two way binding.

The fix is simple , you need to import the forms module to your app module.

-----------app.module----------------------------

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { FormsModule } from '@angular/forms';
import { AppComponent } from './app.component';

@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    BrowserModule,
FormsModule
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

-----------------------------------------------------------------------------

Import the two lines highlighted above and it should work fine .

View full source at here

Cannot assign to 'name' because it is a constant or a read-only property.

Hi Guys,

I have faced an error like "Cannot assign to 'name' because it is a constant or a read-only property." .

The code is as below

------------app.component.ts-----------------------------------
import { Component } from '@angular/core';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html' //// refer app.component.html for property binding
})
export class AppComponent {
  name="";

  testEventBind(userName: string) {
      name=userName;
  }
}

------------------------------------------------------------

I have highlighted the line which causes this error.

All you have to do is to use this keyword , change the highlighted line as below,

this.name=userName;

This should fix the issue.

ERROR in node_modules/rxjs/internal/types.d.ts(81,44): error TS1005: ';' expected.

Hey Guys ,

I have faced this issue on serving a newly created project using angular cli.
ERROR in node_modules/rxjs/internal/types.d.ts(81,44): error TS1005: ';' expected.
node_modules/rxjs/internal/types.d.ts(81,74): error TS1005: ';' expected.
node_modules/rxjs/internal/types.d.ts(81,77): error TS1109: Expression expected.

Solution 1:
Remove the ^ symbol from package.json from
  "rxjs": "^6.0.0",


execute :
npm update

it should work fine.If this doesn't work try this:

Solution 2:
In package.json set the version of rxjs as below:
 "rxjs": "6.3.3",


execute :
npm update

it should work.A working version is here click

Failed to start connector [Connector[HTTP/1.1-8080]]

Hey Guys,

Today I faced an issue while starting Spring boot application .

Full stacktrace is as below :

 o.apache.catalina.core.StandardService   : Failed to start connector [Connector[HTTP/1.1-8080]]

org.apache.catalina.LifecycleException: Failed to start component [Connector[HTTP/1.1-8080]]
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167) ~[tomcat-embed-core-8.5.34.jar!/:8.5.34]
        at org.apache.catalina.core.StandardService.addConnector(StandardService.java:225) ~[tomcat-embed-core-8.5.34.jar!/:8.5.34]
        at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.addPreviouslyRemovedConnectors(TomcatWebServer.java:256) [spring-boot-2.0.5.RELEASE.jar!/:2.0.5.RELEASE]
        at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.start(TomcatWebServer.java:198) [spring-boot-2.0.5.RELEASE.jar!/:2.0.5.RELEASE]
        at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.startWebServer(ServletWebServerApplicationContext.java:300) [spring-boot-2.0.5.RELEASE.jar!/:2.0.5.RELEASE]
        at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.finishRefresh(ServletWebServerApplicationContext.java:162) [spring-boot-2.0.5.RELEASE.jar!/:2.0.5.RELEASE]
        at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:553) [spring-context-5.0.9.RELEASE.jar!/:5.0.9.RELEASE]
        at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:140) [spring-boot-2.0.5.RELEASE.jar!/:2.0.5.RELEASE]
        at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:780) [spring-boot-2.0.5.RELEASE.jar!/:2.0.5.RELEASE]
        at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:412) [spring-boot-2.0.5.RELEASE.jar!/:2.0.5.RELEASE]
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:333) [spring-boot-2.0.5.RELEASE.jar!/:2.0.5.RELEASE]
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1277) [spring-boot-2.0.5.RELEASE.jar!/:2.0.5.RELEASE]
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1265) [spring-boot-2.0.5.RELEASE.jar!/:2.0.5.RELEASE]
        at hello.Application.main(Application.java:15) [classes!/:0.1.0]
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[na:na]
        at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[na:na]
        at java.base/java.lang.reflect.Method.invoke(Unknown Source) ~[na:na]
        at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:48) [gs-spring-boot-0.1.0.jar:0.1.0]
        at org.springframework.boot.loader.Launcher.launch(Launcher.java:87) [gs-spring-boot-0.1.0.jar:0.1.0]
        at org.springframework.boot.loader.Launcher.launch(Launcher.java:50) [gs-spring-boot-0.1.0.jar:0.1.0]
        at org.springframework.boot.loader.JarLauncher.main(JarLauncher.java:51) [gs-spring-boot-0.1.0.jar:0.1.0]
Caused by: org.apache.catalina.LifecycleException: Protocol handler start failed
        at org.apache.catalina.connector.Connector.startInternal(Connector.java:1020) ~[tomcat-embed-core-8.5.34.jar!/:8.5.34]
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) ~[tomcat-embed-core-8.5.34.jar!/:8.5.34]
        ... 21 common frames omitted
Caused by: java.net.BindException: Address already in use: bind
        at java.base/sun.nio.ch.Net.bind0(Native Method) ~[na:na]
        at java.base/sun.nio.ch.Net.bind(Unknown Source) ~[na:na]
        at java.base/sun.nio.ch.Net.bind(Unknown Source) ~[na:na]
        at java.base/sun.nio.ch.ServerSocketChannelImpl.bind(Unknown Source) ~[na:na]
        at java.base/sun.nio.ch.ServerSocketAdaptor.bind(Unknown Source) ~[na:na]
        at org.apache.tomcat.util.net.NioEndpoint.bind(NioEndpoint.java:219) ~[tomcat-embed-core-8.5.34.jar!/:8.5.34]
        at org.apache.tomcat.util.net.AbstractEndpoint.start(AbstractEndpoint.java:1151) ~[tomcat-embed-core-8.5.34.jar!/:8.5.34]
        at org.apache.coyote.AbstractProtocol.start(AbstractProtocol.java:591) ~[tomcat-embed-core-8.5.34.jar!/:8.5.34]
        at org.apache.catalina.connector.Connector.startInternal(Connector.java:1018) ~[tomcat-embed-core-8.5.34.jar!/:8.5.34]
        ... 22 common frames omitted

2019-02-03 20:49:07.448  INFO 7964 --- [           main] o.apache.catalina.core.StandardService   : Stopping service [Tomcat]
2019-02-03 20:49:07.502  INFO 7964 --- [           main] ConditionEvaluationReportLoggingListener :

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2019-02-03 20:49:07.508 ERROR 7964 --- [           main] o.s.b.d.LoggingFailureAnalysisReporter   :

***************************
APPLICATION FAILED TO START
***************************

Description:

The Tomcat connector configured to listen on port 8080 failed to start. The port may already be in use or the connector may be misconfigured.

Action:

Verify the connector's configuration, identify and stop any process that's listening on port 8080, or configure this application to listen on another port.

2019-02-03 20:49:07.510  INFO 7964 --- [           main] ConfigServletWebServerApplicationContext : Closing org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@5af3afd9: startup date [Sun Feb 03 20:49:01 IST 2019]; root of context hierarchy
2019-02-03 20:49:07.512  INFO 7964 --- [           main] o.s.j.e.a.AnnotationMBeanExporter        : Unregistering JMX-exposed beans on shutdown



The fix is simple , just add a property file like this :
application.properties--------------------------
server.port = 8989
--------------------------------------------------------

The error is due to default port 8080 is already in use.
The solution is to change the port number .

ORA-03290: Invalid truncate command – missing CLUSTER or TABLE keyword

The syntax used is incorrect

SQL Error: ORA-00942 Table or view does not exist

If you are getting this error on truncate command , you need to check if you have the privilege to truncate.

OAuth

Hey Guys,

In this blog we will discuss about OAuth . OAuth is used for authentication .

Basic Authentication:
It needs user id and password.
The combination of user id and password is encrypted and added to the header .

The backend validates the authentication data in the headers and allow/block the request.

OAuth 2 :
1. Grant Type : Client Credentials
2 .access token url:
3. Client ID :
4. Client Secret :
5. Scope : api